1. Field of the Invention
Apparatuses and methods consistent with the present invention relate to notifying a user of the state of an external device, and more particularly, to a display apparatus which displays video input from an external device such as a personal computer (PC) so that a user can view the video.
2. Description of the Related Art
Display apparatuses, such as liquid crystal displays (LCDs), plasma display panels (PDPs) and cathode-ray tubes (CRTs), are used to display signals transmitted from external devices such as personal computers (PCs) on screens. Such display apparatuses process video signals which are transmitted from the external devices via connection units using various standards and display the processed signals on screens.
If the display apparatus is not connected to the external device, the video signal may not be received from the external device and hence, no information can be displayed on the display apparatus. Accordingly, it is difficult for users to exactly recognize the connection state of the external device, which may cause an inconvenience to the users. Inventions designed to solve these problems have been disclosed in Korean Patent No. 0139302 and U.S. RE No. 38,537.
However, even when the display apparatus is connected to the external device, if the external device is operated in a display power management signaling (DPMS) mode, that is, in a sleep mode, or if the video signal is not received from the external device due to the external device being turned off, there is no way of knowing the state of the external device. In other words, a user cannot determine whether the external device is switched on or off, is in a sleep mode, or is connected to the display apparatus, which could be an inconvenience to the user.